fix(web): keep messages clear of composer banners

[Bil0000]

What Changed

• Keep the timeline at the live edge when a composer banner increases the bottom overlay height.
• Preserve the current scroll position while the user reads history or a sent-message anchor is active.

Why

Composer banners add reserved space after the timeline can already be at the live edge. The list updated its inset but could keep the old scroll offset, which left the last message hidden behind notices such as Server update available.

This fix adjusts the live timeline when that overlay grows. It leaves manual history reading and sent-message anchoring unchanged.

Checks

• 34 focused tests passed
• Changed-file lint passed
• Web typecheck passed
• Format check passed

Checklist

• This PR is small and focused
• I explained what changed and why

Note

Keep MessagesTimeline scrolled to end when composer overlay height grows

• Adds keepTimelineEndVisibleAfterOverlayGrowth to timelineScrollAnchoring.ts, which calls timeline.scrollToEnd({ animated: false }) when followingEnd is true and overlay height increased; otherwise it is a no-op.
• Wires the utility into MessagesTimeline.tsx via a useLayoutEffect that tracks the previous overlay height and only fires when live following is active and no anchor message is set.
• Adds unit tests in timelineScrollAnchoring.test.tsx covering both the scroll and no-op cases.

^{Macroscope summarized 4eb835a.}

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on this repository. Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro Plus

Run ID: eddeaabc-5163-49d2-b4d3-e053d7bb9626

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[macroscopeapp]

Approvability

Verdict: Approved at 4eb835a

Macroscope's review found this PR approvable — ...

^{You can add or adjust custom eligibility rules. Learn more.}